The immune system protects individuals from infective agents, e.g., bacteria, multi-cellular organisms, as well as cancers. This system includes several types of lymphoid and myeloid cells such as monocytes, macrophages, dendritic cells (DCs), eosinophils, T cells, B cells, and neutrophils. These lymphoid and myeloid cells often produce signaling proteins known as cytokines. Immune response includes inflammation, i.e., the accumulation of immune cells systemically or in a particular location of the body. In response to an infective agent or foreign substance, immune cells secrete cytokines which, in turn, modulate immune cell proliferation, development, differentiation, or migration. Immune response sometimes results in pathological consequences, that is, inflammatory disorders. These inflammatory disorders, which involve immune cells and cytokines, include, e.g., psoriasis, rheumatoid arthritis, Crohn's disease, multiple sclerosis, and atherosclerosis (see, e.g., Abbas, et al. (eds.) (2000) Cellular and Molecular Immunology, W.B. Saunders Co., Philadelphia, Pa.; Oppenheim and Feldmann (eds.) (2001) Cytokine Reference, Academic Press, San Diego, Calif.; Kaufmann, et al. (2001) Immunobiol. 204:603-613; Saurez and Schultz-Cheery (2000) Dev. Comp. Immunol. 24:269-283; van Reeth and Nauwynck (2000) Vet. Res. 31:187-213; Garcia-Sastre (2001) Virology 279:375-384; Katze, et al. (2002) Nat. Rev. Immunol. 2:675-687; van Reeth (2000) Vet. Microbiol. 74:109-116; Tripp (2003) Curr. Pharm. Des. 9:51-59).
The interleukin-1 (IL-1) family of cytokines contributes to the pathology of inflammatory disorders and proliferative conditions, e.g., arthritis and cancer. Cytokines of the IL-1 family include IL-1alpha, IL-1beta, IL-1delta, IL-1epsilon, basic fibroblast growth factor, IL-18, CREG and CREG2. IL-1alpha and IL-1beta are biosynthesized as 31 kDa polypeptides that are further processed to mature 17 kDa forms, while IL-1delta and IL-1epsilon appear not to possess a distinct pro-form (see, e.g., Debets, et al. (2001) J. Immunol. 167:1440-1446; McMahon, et al. (1997) J. Biol. Chem. 272:28202-28205; Irikura, et al. (2002) New Engl. J. Med. 169:393-398; Kim, et al. (2002) J. Biol. Chem. 277:10998-11003).
The IL-1 family also includes IL-1 receptors, i.e., IL-1RI, IL-1RII, and IL-1R accessory protein (a.k.a. IL-1R1, IL-1R2, and IL-1R3, respectively). IL-1alpha and IL-1beta trigger cell signaling by binding to IL-1R1, while IL-1RII can function as a molecule that absorbs circulating ligand. IL-1 receptor antagonist (IL-1Ra), another IL-1 family protein, binds to IL-1 receptor without transmitting a signal and serves as an inhibitor of IL-1. IL-1ra and IL-1delta play similar roles in antagonizing signaling through receptors, i.e., IL-1ra antagonizes IL-1alpha-mediated signaling via IL-1R1, while IL-1delta antagonizes IL-1epsilon-mediated signaling via IL-1R6 (see, e.g., You, et al. (2001) New Engl. J. Med. 193:101-109). Debets, et al. (2001) J. Immunol. 167:1440-1446; Apte and Voronov (2002) Sem. Cancer Biol. 12:277-290; Wong, et al. (1997) Proc. Natl. Acad. Sci. USA 94:227-232).
IL-1 family members play a role in inflammatory conditions, e.g., rheumatoid arthritis, psoriasis, asthma, chronic obstructive pulmonary disorder (COPD), sepsis, and inflammatory bowel disorder (IBD). Rheumatoid arthritis (RA) is a common chronic inflammatory disorder characterized by degradation of joints, e.g., the synovial membrane, cartilage, and bone. The disorder strikes about 1% of the population and cannot be cured. IL-1 stimulates a number of cells involved in arthritic inflammation, e.g., fibroblasts, osteoclasts, chondrocytes, and neutrophils, which may show abnormal proliferation and release enzymes causing joint destruction (see, e.g., (Debets, et al. (1997) J. Immunol. 158:2955-2963; Lacey, et al. (2003) Arthritis Rheum. 48: 103-109; Chung (2001) Eur. Resp. J. Suppl. 34: 50s-59s; Freeman and Buchman (2001) Expert Opin. Biol. Ther. 1:301-308; Dinarello (2000) Chest 118:503-508). Krause, et al. (2002) J. Immunol. 169:6610-6616; Choy and Panayi (2001) New Engl. J. Med. 344:907-916; Woolley (2003) New Engl. J. Med. 348:1709-1711; Williams, et al. (2000) New Engl. J. Med. 164: 7240-7245; Feldmann and Maini (2001) Annu. Rev. Immunol. 19:163-196; Lacey, et al., supra; Niki, et al. (2001) J. Clin. Invest. 107:1127-1135; Attur, et al. (2000) J. Biol. Chem. 51:40307-40315).
Proliferative disorders are the second most common cause of death in the United States (Anderson (2002) National Vital Statistics Reports 50:1-86; Toribara and Sleisenger (2003) New Engl. J. Med. 332:861-867; Janne and Mayer (2000) New Engl. J. Med. 342:1960-1968; Fuchs and Mayer (1995) New Engl. J. Med. 333:32-41). Cytokines of the IL-1 family have been implicated in the control and pathology of proliferative disorders, i.e., cancer. IL-1 modulates progression through the cell cycle, e.g., by changing expression of cyclin-dependent kinases and cyclin-dependent kinase inhibitors. High doses of IL-1beta promote tumor invasiveness, while low doses can promote immune eradication of tumors (see, e.g., Zeisler, et al. (1998) Eur. J. Cancer 34:931-933; Yoshida, et al. (2002) Brit. J. Cancer 86:1396-1400; Nesbit, et al. (1999) Oncogene 18:6469-6476; Dinarello, et al. (1998) J. Leuko. Biol. 63:658-664; Apte and Voronov, supra; Saijo, et al. (2002) New Engl. J. Med. 169: 469-475; Murai, et al. (2001) J. Biol. Chem. 276:6797-6806; Koudssi, et al. (1998) J. Biol. Chem. 273: 25796-25803; Zeki, et al. (1999) J. Endocrinol. 160:67-73; Osawa, et al. (2000) J. Biochem. 127:883-893).
There is an unmet need to treat inflammatory and immune disorders. The present invention fulfils this need by providing methods of using agonists and antagonists of IL-33 or IL-33 receptor.